When London Shook
by Floppy Katana
Summary: When Mycroft comes to 221B Baker Street bearing an ominous message, Sherlock and John must protect the city they love from a rampaging bomber who is out for revenge.
1. Chapter 1

Screeeeeeeech!

John bolted awake, tousle-haired and disheveled. He fumbled for his gun which lay just inside his drawer and leapt to his feet, charging through his bedroom door.

Screech!

The noise came again from somewhere before him. But, given the pervasive dark, he had trouble localizing the sound.

John furrowed his brow. The scream-like noise was somewhat familiar.

Then it came again and John realized what it was. Flicking on a light irritably with the barrel of his gun, John stood down.

There was his flatmate, perched in a chair overlooking Baker Street. Without turning, Sherlock played another chord with a flamboyant whirl of the bow.

"Why do you have your gun, John?" he said.

"Well, I don't know," replied John sarcastically. "Why're you playing your violin at two in the morning?"

"I'm thinking about the case," said Sherlock, starting a Bach sonata. "As of yet, the answer eludes me. I need to think."

"Here I was thinking someone was dying and you tell me you're thinking."

John walked up and snatched the bow from Sherlock's hand. Laying his gun on the table, John secured the bow into its case.

"Now go back to sleep. I keep saying that you'll be able to think better on a night's rest."

Sherlock sighed in distaste. "That's not how I function. A minute spent sleeping is a minute lost."

John glared at Sherlock, who returned the look.

"Fine. You can stay up," said John eventually, "but no more violin."

"Fair enough," grumbled Sherlock, surrendering his violin to John. His hands formed a line down the center of his face as he turned his head downward. His face was silhouetted by the dim light of the streetlights.

John picked up his gun, turned off the light, and walked back to his room. He climbed back in bed but had difficulty sleeping. The fear and surprise of hearing the supposed scream had shocked him and sent the adrenaline coursing through his veins. This life working as a consulting detective's blogger was certainly not without its danger and drama.

But it was undoubtedly better than the life he had led before he had met Sherlock. His limp, his PTSD attacks, his boring counseling sessions… they had, for the most part, gone away. His dreams were no longer full of the woes of war. And when you were Sherlock Holmes' best (and only) friend, no day was boring.

The next day certainly wasn't. As John raided the refrigerator for anything edible and found a plastic bag full of what looked like blood, he decided that he had quite lost his appetite.

Sometime in the early morning, Sherlock had solved the case he has been working on ("It was the banker!"). Though he had made good on his promise not to play the violin, he hadn't taken John's advice about getting enough sleep. Two dark circles shadowed his eyes, but he didn't seem to be affected by the sleep deprivation. Or from lack of food, it seemed.

"We mustn't starve ourselves to death," said John, who had gotten over his loss of appetite. "How do you feel about crepés?"

Sherlock shrugged, poring over his microscope and adjusting the slide. This, John had come to learn, was Sherlock's way of saying yes.

A few minutes later, the duo emerged from the door and walked down Baker Street towards the new creperie. It was a chilly winter morning with a hint of snow in the air. Even through his many layers of clothing, John felt the bite of the wind and longed for Sherlock's heavy coat.

They were both relieved when they stepped through the creperie's door and heard the inviting jingle of the bell.

They took a table near the window and ordered their crêpes.

As soon as the food arrived, they tucked in. Sherlock wolfed down his stack of crêpe isn under a minute, whilst John had hardly started.

Sherlock decided watching John eat was boring, so he turned his attention to the door.

"Interesting," he remarked.

"What?" said John through a mouthful of crêpe.

"My brother is here."

John turned around to study the new entrant. He had only met Mycroft Holmes once and didn't know much about him at all.

Without looking around, the black-clad man stalked over to a table on the other side of the room, where he began to examine the menu studiously.

"What's he doing here?" asked John. "Does he want to talk to us?"

"Maybe," said Sherlock mischievously. "Or he could just be out for crepes. The widening of his girth does seem to suggest the consumption of crêpes on a regular basis."

John frowned. This was un-Sherlockish.

"Of course he wants to talk to us, John!" said the genius. "Why else would he be tapping a message in Morse Code with his fork?"

John pulled the face he used solely when Sherlock's abilities astounded him.

"What did he say?"

"He said to meet him at 221B Baker Street in ten minutes," said Sherlock.

After paying for their crêpes, the detective and his blogger walked back to their flat. Fluffy white snow had begun to fall and their footsteps left indentations in the snow.

"Hmmm," said Sherlock, as they came to their door. "Mycroft has not followed us."

"You can tell that without looking behind you?" asked John incredulously.

"It's not difficult at all. When will you start observing, dear doctor?" said Sherlock. "The taxi's windshield acts as a mirror."

John did a facepalm as he realized how obvious the answer had been.

They walked into the building and up the stairs to their flat. Sherlock walked into the kitchen to find his microscope still set up. John, with little else to do, sat across the table from the detective and updated his blog.

He wanted to ask Sherlock why Mycroft hadn't followed them back to 221B, but the detective appeared so involved with his microscope that John didn't want to interrupt him.

Then they heard a knock at the door far below. They heard Mrs. Hudson's high-pitched, "I'm coming," and the door swinging open.

"Gangsters?" asked John. "Assassins, crime rings, brigands?"

"No," said Sherlock, listening intensely to the sounds from downstairs. "Just delivery men."

And, just as Sherlock had said, they heard a deep voice say, "We have a delivery for a Mr. Sherlock Holmes."

"You poor men," rang Mrs. Hudson's shrill voice. "That box must be unbearably heavy. I'm sure that Sherlock won't mind if you leave it down here. I'm so glad he's getting another refrigerator. He keeps mixing food with spare body parts!"

They heard the distinct closing of the front door.

"Let's go see what it is," said Sherlock, putting his hand on the doorknob. "Oh. You might want to bring your gun just in case."

"Oh, Mr. Holmes!" cried a startled Mrs. Hudson as Sherlock swung open the door. Her hand was raised as if she was about to knock. "You startled me! There's a package for you downstairs."

They descended without a word. John fingered his gun nervously.

The package was quite large and looked rather heavy. It was sealed by the normal mailing tape of the London area.

Sherlock approached the box cautiously, just as it shook.

"Can someone let me out of here?" said a disembodied voice. "Mrs. Hudson, is that you?"

"Mycroft!" yelled Sherlock, hurrying forward to the box. "What're you doing here?"

John took out his army knife and cut along the joints of the box. Then he pulled off the top of the box.

Mycroft sprang out like a jack in a box, gasping for breath.

"Oh, Mycroft!" said Mrs. Hudson, crestfallen. "I hate to sound disappointed, but I thought you were a refrigerator. Here, let me make you some tea!"

And she bustled away like nothing out of the ordinary had happened. Mycroft, Sherlock, and John walked back up the steps to the flat.

"To what do we owe the unexpected drop-in?" asked Sherlock, sprawling back on his favorite armchair.

"I was just out for crêpes, like you and John," responded Mycroft.

"Yeah, right. And if that is the case, why did you find it necessary to mail yourself to us?"

John barked with laughter at Mycroft's embarrassed face, but quickly stopped. He knew that Mycroft wouldn't have mailed himself in unless he had to hide his entrance. This meant that they were probably being watched. Fortunately, Sherlock had drawn the shades before they had left the room.

"You know, I presume," said Mycroft, "Of the package bombs that ravaged that city in Texas?"

"Brother, I was the one that tipped off the police as to the identity of the bomber!" yelled Sherlock.

This was news to Mycroft. His expression turned grave. "My network has informed me that there are moves afoot to do a similar thing here in London."

"Yippee!" cried Sherlock, hopping up from his chair.

"You're excited about terrorism?" said John incredulously.

"Of course he is," said Mycroft, "he's Sherlock. Anyway, I didn't mail myself to you just to tell you that."

"Why did you mail yourself here?" asked John.

"I'm placing you under level six surveillance. Your flat will be under watch constantly by some of my men. You are not allowed to leave."

"Why?" said John. "Why would we be targeted?"

"The Austin bomber had an accomplice. Surely he harbors animosity towards Sherlock due to the fact that Sherlock was responsible for his co-conspirator's capture."

"I don't like it," muttered Sherlock, looking wistfully at his violin case.

"What?" asked Mycroft.

"You… helping us. It's unnatural."

"I'm glad you appreciate all I've sacrificed on your account. Now, I really must be going."

Mycroft disappeared down the stairs and they heard him walk out into the street. Apparently, the street was already being watched by Mycroft's agents, as he didn't keep up the secrecy he had maintained before. He climbed into a waiting car. They watched it hurtle away into the heart of London through a gap in the shades.

It didn't take long for Sherlock to get bored.

His experiments, for the moment, were at an impasse. There was nothing but Mrs. Hudson's tea to drink and little but spare body parts to eat. He looked over at his violin case which John had fastened last night but couldn't manage to extricate himself from the armchair.

John busied himself reading the newspaper, but that didn't captivate his attention for long. There was nothing for it. He was terribly, insanely bored.

"Let's get out of here," he said.

"That's the smartest thing you've ever said."

"How will we get out?" asked John. "If we leave, Mycroft will know immediately and send his men after us."

"I have an idea," said Sherlock.

Two cardboard boxes rattled along in the trunk of a delivery truck. The truck pulled into a small parking lot and came to a stop.

"I don' know why you needed ter be transported like this, Mr. 'Olmes," said the gruff driver. He opened up the boxes and the duo climbed out.

"No questions asked, O'Brien. That's the arrangement," said Sherlock, dusting off his pants.

"All right," said the truck driver. "Not a word."

After paying their shady-looking smuggler, John and Sherlock hurried down the street.

"It's good to be out, even if we're not doing anything," said John.

"Something tells me that that will not be the case for very long," replied Sherlock.

And, just on cue, a deep explosion sounded in the distance.

"Finally!" yelled Sherlock. They sprinted off down the street towards the billowing smoke from the bomb.

They rounded the street corner and saw that the first responders were clustered at the base of an apartment. A fire engine was parked out front and was spraying water onto the burning building. Shrapnel was scattered across the street and a thick, stuffy dust clouded the air.

Sherlock held his scarf over his mouth to avoid breathing in the dust.

"Hmm," he said, bending low to the ground to study the debris. "This looks like remote detonation targeting a specific individual that lives in that building."

Soon the firefighters and first responders had stopped the fires and were taking the injured people out of the apartment. As they emerged, Sherlock examined each person.

"Hmm… he's innocent… recently adopted a dog," said Sherlock, looking at an elderly man with a broken leg. His eyes rapidly scanned the injured people, roving around for anything that could be a clue. "This is odd. None of these people look like targets."

"Hang on, Sherlock," said John. "I think I know why. Maybe the bomber set this up, knowing that you would be drawn here."

Understanding dawned on Sherlock's face just as the red dot signaling a sniper appeared on his arm.

"Jump!" he yelled, leaping over a remnant of the wall and dragging John behind him.

Bang, bang, bang! The gunshots rang throughout the street, but not many people noticed them; they were too busy tending to the injured or setting up crime scene tape.

Sherlock and John hunkered behind the broken wall, trying to avoid the barrage of whirring bullets that whizzed past the makeshift bunker.

"Sherlock! Can you see who it is?" cried John.

Sherlock chanced a glance above the wall and saw that there was an indistinct figure standing on a balcony of a hotel opposite them.

"Here, I have my gun," said John. "I'll try to shoot him."

John settled onto his belly and took out his gun. He poked the barrel over the wall and aimed it at the figure.

Bang!, came the gun. Suddenly the gunshots stopped.

"I think I hit him," said John wearily, coming out from cover. He looked up to the opposite building expecting to see the shooter, perhaps doubled over in pain, but was instead greeted with an empty balcony.

"You missed," said Sherlock blankly.

"And you fell for the trap!" retaliated John angrily. Sometimes Sherlock could be so insensitive.

Sherlock pretended not to hear. Just then, the police noticed them.

Inspector Lestrade walked forward, quickly deducing what had happened from the the bullet-strewn ground. He was no novice when it came to solving crime, through the presence of Sherlock Holmes so often made him seem so.

"What the…?" he said.

"Excuse us, Lestrade, we have places to be," said Sherlock. And he sprinted across the street, closely followed by John.

After barging through the door, they found themselves in a large lobby. A grand chandelier hung from the ceiling, glittering like a thousand diamonds.

As they rushed in, they disregarded the dumbfounded lobby attendant and hurtled over to the elevator. Sherlock roughly pushed out the occupants and stepped inside.

"Tenth floor," said Sherlock, punching in the corresponding number in the elevator.

"I thought he was on the eighth?"

"Seventh," corrected Sherlock.

"But why are we going to the tenth floor?" asked a bewildered John.

"Argh! Must I explain everything?" said Sherlock as the doors whooshed open. "To the roof access!"

They climbed up the ladder and popped open the hatch, coming out onto the roof.

"Sherlock, I don't understand…"

Sherlock gave John his trademarked "of course you don't understand" face.

"From up here, you can see everything that happens below. Important things," explained Sherlock, running through a maze of heating units to reach the back of the building. "Like that!" he added.

And there was the shooter, hurriedly climbing down the fire escape and trying to get to a getaway car parked at the bottom. Quickly, Sherlock wheeled around and grabbed a coil of electrical wire.

 _Can support my weight_ , flashed the words in his mind.

He tied one end to the railing of the fire escape and leapt off the edge of the building, paying no heed to John's objections.

Using his feet to push off from the wall, Sherlock slid down the wire. Though his hands were in agony from the ropeburn, he paid them no mind. There was no time to get caught up with trivial things like pain when there was a criminal to be caught.

Soon the rope became taut; he had come to the end of the wire. He clambered into the fire escape one floor above the shooter.

The masked man looked up in surprise at the loud clang. He half-raised his gun but stumbled forward. He windmilled his arms to keep his balance.

Though he was able to keep his footing, it came at a price; his gun flew away and clattered down the stairs.

Disregarding it, he redoubled his pace. Now he only had one more set of stairs before he could make his getaway. Sherlock continued down the fire escape but watched with dread as the masked man came to the ground level and dashed towards his car.

Just as the criminal was opening the car door, John's gun exploded overhead and the bullet shot towards the man.

He screamed but managed to leap into the car and shut the door. By that point, Sherlock had nearly caught up. But then, the shooter floored it and the car shot away. Even Sherlock, with his abnormally long legs, couldn't keep up for long.

Sherlock returned to the bottom of the fire escape, where John had just emerged.

"Good shot," said Sherlock. "I think you wounded him."

"Thanks," mumbled John.

"This is so exciting, isn't it?" said Sherlock energetically, picking up the shooter's lost gun and starting to walk around the hotel to the front of the building.

"Someone's trying to murder you, Sherlock," John pointed out (not that he thought in the slightest that it would change the detective's mind).

"Yes… now that we know the intent, it will be much easier to predict his next actions," said Sherlock. "Hello, chaps!"

A small group of inspectors from New Scotland Yard had walked up, Detective Inspector Lestrade at their front.

"Just _what_ are you doing with that gun?" he yelled at Sherlock, red in the ears.

"Nothing, really. I was going to bring it to the lab at St. Bartholomew's Hospital and run some DNA scans. That way, if we get our hands on the man, we can confirm that he was the shooter."

"You can't just walk around the streets with a gun!"

"Are you offering us a ride?" asked Sherlock in his manipulative way.

Lestrade sighed. He didn't want to get into an argument today, especially not with Sherlock.

"Alright. Donovan, you drive them over," relented Lestrade reluctantly.

They climbed into the back seat of the police car. Sherlock held it up to the light to study the weapon.

"Hmm. John, you know about weapons. Tell me what you can about this."

John bit his lip, as was his custom when faced with a question. "AR-15. Equipped with a scope."

Sherlock shrugged his shoulders in disappointment. "Is that all?"

"Er," said John. He tried to think of how his flatmate went about deducing and turned the weapon over in his hands. "It was… erm…"

"Two parallel scars in the paint running down the muzzle," said Sherlock quick-fire. "They've been painted over by the owner with a slightly different shade of black. The fact that the owner kept his gun clean tells me that he was part of an elite group of criminals, most likely a crime ring or secret organization. Though the paint is not an exact match, the fact remains that the owner made the attempt.

"Next, observe the wear marks on the handles. Given the marks on the back left and front right side, I can tell you safely that this man is left handed.

"Last, note the scope. The hinge is loose and well-lubricated with high-quality oil. This gun has been used for crime many times and the owner has never been caught by the police. This is a weapon of a serial killer, a consulting serial killer, if you will."

"Amazing," said John. Sherlock's deductions never ceased to amaze him.

"Elementary," replied Sherlock. "Here's the hospital."


	2. Chapter 2

Author's Note: The plot thickens… Keep a lookout for the clues. Try to solve the mystery before Watson and Holmes do! Let me know what you think about this story by writing a review. Thanks for reading!

Sherlock and John walked up the steps to the doors of St. Bartholomew's Hospital. The attendant at the front desk didn't even bother to ask why Sherlock was carrying a firearm. After all, it wasn't the strangest thing she had seen him carrying into the hospital. The award for that category probably went to the riding crop.

They made their way straight into the DNA lab, where tests regarding forensics and ancestry were done. The room looked like a much cleaner version of Sherlock and John's kitchen in 221B Baker Street, complete with rows of microscopes, electrophoresis tanks, and all kinds of medical paraphernalia.

Sherlock threw the rifle none-too-gently onto a table and took a swab from a nearby container. Using the swab, he took a sample from the trigger, which he had been careful not to touch for fear of infecting the sample, and ran it through a DNA sequencer.

"I've input the DNA code into the computer," said Sherlock. "It won't be done for a few hours, but-"

He trailed off, quirking his head as if he was straining to perceive something at the edge of human hearing.

John tried to listen for any sound out of the ordinary, but the years of shelling in Afghanistan had greatly reduced his hearing ability and he listened in vain.

"What is is?" asked John.

"It's coming from over here," said Sherlock, walking over to a cabinet just below the window. He knelt down and tried to open the cabinet.

"Ugh," said Sherlock, straining his muscles against the cabinet handle. "It's locked. John, hand me that hairpin, will you?"

As John bent down to grab the hairpin, a low, rhythmic ticking sound filled his ears. His heart sank with dread; it was unmistakably the ticking of a bomb.

Sherlock picked the lock with ease. With a heavy tug, Sherlock wrenched open the large cabinet.

Inside ticked a large, menacing bomb, strewn with a jumble of colorful wires and equipped with a central console displaying the time until detonation. The numbers that glowed crimson on the screen read:

00:00:03 

"Oh, no," breathed John.

In a split-second decision, John leapt forward into the cabinet and wrapped his arms around the bomb. He had no idea what made him do it; there was no way he could possibly smother it. That kind of smothering only worked with small bombs, like grenades.

John closed his eyes, barely registering the last two ticks of the clock and bracing for the inevitable explosion.

But it never came.

Hardly daring to breathe, John frowned. The ticking had stopped, but the bomb had not exploded. In a daze, John emerged from the cabinet. Sherlock was halfway across the room, still sheltering behind a flimsy lab table that would've done little to protect him if the bomb had indeed gone off.

"What?"

Sherlock pulled herself from behind the table and walked over to where John stood shuddering.

"You tried to smother it!" yelled Sherlock angrily, turning on John. "What were you trying to achieve with that?"

"No need to get angry, Sherlock," responded John, who hadn't expected Sherlock's enraged response. "I just… did what I was trained to do."

"In the army they trained you to smother grenades," said Sherlock, "But if a bomb of _that_ size had gone off, an attempt to smother it would have resulted in your innards getting splattered all over."

John had no response to that. Instead, he made his way back over to the unexploded bomb.

The bomb was silent and unthreatening. Sherlock stepped forward and saw that a red wire was loose from the main device.

"Whoever set this was no expert in bombs," said John, eyeing the loose wire.

"That's odd. From the complexity of the first bomb, I would say that the bomber was an expert in pyrotechnics," responded Sherlock.

John, meanwhile, had called the police at New Scotland Yard. "They're on their way," he said. "How would someone get access to this room to place the bomb? The window is locked. This room is under constant surveillance by the security cameras."

Sherlock looked up from the bomb to scrutinize the lab. There were security cameras stationed around the perimeter of the room.

"Let's access the video from these. Maybe, if the criminal was too lazy to cover their tracks, we can figure out who it is," asked Sherlock, gesturing at the security cameras.

They walked to the security control room that was behind the front desk. Sherlock elbowed the security guard out of the way, flashing Lestrade's stolen ID card at him.

Quickly, Sherlock pulled up a sped-up video of the DNA lab that showed the past few days. As the images came to a stop, Sherlock said, "How unusual. No one has accessed that cabinet in the past four days."

Sherlock pressed a few buttons and selected the video from five days ago.

"Hang on," said Sherlock, pausing and replaying the playback. "What was that?"

John leaned in closer to see the clip Sherlock had selected. This camera angle showed the window and the cabinet just beneath it.

The only thing they could see through the window was empty darkness. Then, they saw someone wearing a clean lab coat walk up to the cabinet. The figure leaned down and placed a large object inside. The person hunched over the cabinet and secured the lock they had seen. Then the figure turned away towards the door and walked out of sight.

"Go back a few seconds," said John.

Sherlock did as John said and paused the playback just as the figure on the small screen turned around. He zoomed in to focus on the bomber's face.

"What!" cried Sherlock, looking closer in disbelief. "That's impossible."

"It's her," said John, equally confused. "Molly."

"This… doesn't… make… sense!" said Sherlock, rubbing his temples in time to the words. "Molly can't possibly…"

Sherlock trailed off and hurried out of the security room.

"Where are you going?" asked John, following his flatmate closely.

"Off to deduce something," he responded, taking off in the direction of the offices. They came to Molly's office near the morgue.

"Ah," said Sherlock, his eyes rapidly scanning the desk and taking in the many details. "It appears that Molly is not here today. As a matter of fact, she hasn't been here for the past four days… ever since the bomb was placed. Finally! The pieces are coming together!"

Sherlock rammed his eyes shut and stood stock still. His arms were raised in front of him like a zombie and he moved his hands to and fro as if he was assembling a large, invisible puzzle.

Within a minute, his eyes popped open. "Got it!" he said cheerfully. "As soon as Molly placed the bomb, she crept off to set up more bombs around London. It didn't matter where she went, so long as she vacated the building. Since Molly worked in the DNA lab, she knew that that cabinet was rarely opened and used it to hide the bomb inside. Because this bomb was set by a timer, I get the idea that she intended for the bombings to continue, even after we were supposed dead by the first bomb."

"But… Sherlock, this is _Molly_ we're talking about," said John, who was having a hard time believing the whole thing. "Since when was she an undercover bomber and sniper? And since when did she want to kill us? If she had harbored this intent at us for so long, why didn't she kill us sometime earlier when our backs were turned?"

"Maybe she had to wait for a sign from abroad to signal that the go-ahead was safe."

"You mean the Austin bombings?" asked John.

Sherlock frowned. "Not exactly," he said. "Once the bomber's strategy against the Austin police was supposedly successful - and it would've been successful, mind you, if I hadn't intervened - the bomber signaled to Molly part of the information she needed to proceed in London. But when he was captured by the American police, he was unable to send the last part of the recipe for the bomb, and Molly's time bomb failed to go off as a result."

"Originally, I suspect, the bombs in London were intended to be just random terror strikes. But when I captured the Austin bomber, I angered Molly and transferred the intent of her bombings to me."

"I don't believe it," said John dubiously. "Frankly, I _can_ ' _t_ believe it. I haven't known Molly for all that long, but it doesn't seem to me that she could bring herself to harm anyone, much less be an undercover bomber."

"Sometimes the worst of criminals are hidden under the guise of innocence," countered Sherlock.

"How do you explain the wire, then?" said John. "If Molly was really an experienced bomber, she wouldn't have made a mistake. And why did she not erase the video from the security logs to hide her identity?"

"Simple. Even the most practiced criminals make mistakes, especially if they are under stress. Take, for example, the cabbie in the case you call "A Study in Pink." He was completely incognito until we discovered that he had made a slip-up with the pink bag. Molly made the same error, albeit somewhat earlier in the chain of events. Next, she did not feel it necessary to delete the security camera footage because they would've been deleted automatically had the bomb exploded as she intended.

"My theory is that Molly created the apartment bomb as a diversion to keep us away from the hospital while she destroyed her evidence. Moreover, any deletion in the logs by an inexperienced hacker would result in an immediate alarm to the chief of security."

John nodded slowly. Much as he hated to admit it, Sherlock's conjecture was sound. He abhorred the idea that Molly might be a criminal. It was just too much for him to fathom.

He followed Sherlock into the area surrounding the desk. Sherlock ransacked the cabinets of the desk and rifled through their contents.

While John waited patiently for Sherlock to find anything of importance, his eyes drifted over to a stack of papers on Molly's desk. A particular word on the first page caught his eye. He reached down and picked the sheet up.

It looked like a death notice Molly had logged, the most recent one since her disappearance, judging by the date stamped in the corner. The first few lines were written in Molly's neat handwriting, whereas the majority of the words were slanted to the right and scrawled savagely, as if the pen that had written them had been on fire.

Patient: Alfonso Alberto Aragon

Time of death: 19:00

Cause of death: Heart attack

Witness: Molly Hooper

Summary:

 _At seven o'clock, the patient died from a heart_

 _attack. The patient had previously said his good-_

 _byes to his living relatives, including a young_

 _man who was his only living son. The patient_

 _had a pale countenance, a normal occurrence_

 _given the circumstances of his death. Just_

 _under his eyes there was a slight greenish and_

 _navy blue tint. There were no abnormalities_

 _save the discoloring. I will check in lab for the_

 _meaning of this bruising. Perhaps I will resort to_

 _Sherlock's riding crop technique to find answers._

 _Because of this unusual bruising, I have had to_

 _occupy the complaints of the patient's son, who_

 _may be concerned that the discoloration and the_

 _bruising will remain during the funeral. More data_

 _in the DNA Lab._

Meanwhile, Sherlock had risen from his cabinet-raiding.

"What's that?" said Sherlock, taking the sheet from John.

"It's the last death notice Molly wrote before she left. She mentioned your name in the middle… something about a riding crop?"

But Sherlock didn't acknowledge. He was transfixed, staring at the letter like it was made of pure gold.


	3. Chapter 3

"What is it?" asked John. "What does it mean?"

Sherlock tore off in the direction of the morgue. They clattered straight through the main doors into the gloomy room. It was a very sinister place, with rows of bodies zipped up inside body bags lined up neatly in the order they had arrived.

Sherlock strode over to a body in the corner, unzipped it, and peered at the body. "Ah," he said. "As I suspected. Clever, Molly! Now, John, you are probably about to explode with questions. Let me explain. At seven o'clock, she was attacked by a man with a gun. She asked us to save her and said that there is bomb in the DNA Lab."

"What?" said John, thoroughly confused.

"That was the message Molly sent! You see, this here is Alfonso Aragon," he said, pointing at the corpse. "Do you notice how little bruising there is? I am an expert in post-mortem bruising, and this is not at all how Molly described it in her report."

"I still don't see how you got that message from the original document," said John uncertainly.

Sherlock took out the paper and pointed at the column of words.

"It's clear as day to me," said Sherlock with a hint of snarkiness. "It's an easy code, really. Molly is no code maker, but she got the message across without alerting her captor, and that is all that counts in a code."

Sherlock looked around for a pen. John didn't have one, so Sherlock took one from the pocket of Aragon's hospital gown. Then, he underlined certain words on the crumpled page.

At seven o'clock, the patient died from a heart

attack. The patient had previously said his good-

byes to his living relatives, including a young

man who was his only living son. The patient

had a pale countenance, a normal occurrence

given the circumstances of his death. Just

under his eyes there was a slight greenish and

navy blue tint. There were no abnormalities

save the discoloring. I will check in lab for the

meaning of this bruising. Perhaps I will resort to

Sherlock's riding crop technique to find answers.

Because of this unusual bruising, I have had to

occupy the complaints of the patient's son, who

may be concerned that the discoloration and the

bruising will remain during the funeral. More data

in the DNA Lab.

"Do you understand now?" asked Sherlock. John nodded in response.

"Oh, this disproves that theory quite well," said Sherlock. "Of course! I'm blind! I knew there was something more to the story."

"The problem isn't blindness, Sherlock, as much as it is trust," snapped John. "Maybe you should put a little more faith into your friends before going off on some wild goose chase to prove that we're all secret undercover criminals."

Sherlock opened his mouth to protest, but the dangerous look on John's face deterred him from arguing.

"Do you… trust me?" asked Sherlock, looking very confused.

"Of course I do," responded John. "That's what friends do. They trust each other."

Sherlock, for the first time John had ever seen him, looked completely baffled. John couldn't tell what was going inside Sherlock's head but it seemed to him that Sherlock was trying to solve the most difficult mystery he had ever encountered. His eyes were darting around connecting puzzle pieces in his head and his face was contorted in concentration.

"Sherlock," said John. "Are you OK?"

Sherlock slowly came out of his reverie, seeming to realize that he was standing in the morgue and John was standing in front of him.

"Yeah, of course I'm OK," said Sherlock in a slightly higher voice than normal. "We're on a case, right?"

John nodded, bewildered by the turn of events.

Suddenly, Sherlock was back in his element. He looked down at Aragon's body and replaced the pen inside his pocket. As he did so, the outline of a rectangular shape showed up against the fabric. Sherlock slid the shape from the body's pocket and saw that it was a note.

It was a small scrap of paper torn roughly from a notebook bearing only two words:

Waterloo Bridge

"Yes," cried Sherlock joyfully, zipping up the body bag and walking out of the room. "Because the bomb placed here would have supposedly destroyed us, the bomber must have already laid plans to continue with the random terror strikes."

"What about Molly, though?" said John as they stormed through the front door. "She's being held captive. Shouldn't we try to rescue her?"

"That is not the most pressing concern," replied Sherlock, hailing a cab.

"When the bomber realizes that the bomb didn't go off, he'll blame Molly. He might try to kill her."

"We cannot concern ourselves with that for the time being," said Sherlock stoically. "Averting this explosion is more important than rescuing Molly. And as far as we know, Molly is already dead."

On that somber note, they climbed into a cab and directed the driver to the Waterloo Bridge. Despite the traffic, they soon arrived on the banks of the Thames, a few hundred meters from the base of the bridge. In five sweeping arches, the bridge elegantly spanned the river.

But Sherlock and John paid the marvellous feat of engineering little attention, instead focusing on the small pier that extended out into the water. A small rowboat was docked at it. After a quick conversation with the owner, John and Sherlock climbed aboard and rowed the small boat towards the hulking bridge. Little chunks of ice swirled past their oars as they rowed by.

They made for the leftmost concrete support. They rowed in a circle around the massive pier, looking up at the small parapet formed between the two concrete struts that held up the bridge. They saw no sign of the bomb. They did the same for the other three piers, finding nothing.

"They must not have placed it yet. We'll stay nearby until it is placed."

He directed the boat to the nearby shore.

"Are you certain that it is not a false trail?" said John, using the oar to pull their boat forward. "The bomber might've forced Molly to write it to draw us off the pursuit."

"I am certain."

John waited for the explanation.

"I am speculating that Molly asked the bomber to go back in and complete her work under the pretense that people would suspect foul play if she left her work incomplete. I believe that the bomber accompanied Molly inside the building using a back entrance and watched her from a distance as to not appear suspicious. Thusly, Molly went over to the body in the morgue, writing the coded death notice with her back turned to the window, where the bomber watched. She was able to slip the note into the dead man's pocket because she was positioned in front of the body."

"Why wouldn't the bomber follow Molly into the morgue?" asked John.

"There are many possible explanations," responded Sherlock. "But there's not enough time for them now. Unless I'm very mistaken, our quarry approaches."

John followed Sherlock's gaze and saw a small, two-person motorboat coming down the river. Sherlock and John dragged the boat into the water and stepped inside, picking up their oars.

"We'll hide behind this pier," said Sherlock, pointing at the nearest support. "You have your revolver, I hope?"

John checked the holster that was hidden under his jacket. It was comforting to feel the shape of the handle, even though it was covered by several layers of fabric.

They rowed back out into the river and came to a stop behind the concrete pier, their little craft bobbing up and down in the sheltered water. Cars hurtled along overhead and the boat Sherlock had spotted earlier came ever closer.

There looked to be two people on board. One was in the stern, handling a motor. The other held a fishing rod and was looking out over the bow. Soon, the motorboat came even with the bridge.

"Let's go," said Sherlock, taking his oar.

Using the concrete piers to hide their approach, they rowed their boat to the pier behind which the other vessel had vanished.

With a nod from Sherlock, they rowed around the pier furiously. But instead of encountering the other boat, they found the space under the arch empty.

"There they are!" yelled John, pointing at a rapidly escaping motorboat. "They must've seen us coming!"

"It was the man who rented us the boat," said Sherlock, "They must've asked him if he had seen anyone fitting our descriptions."

He dug his oar into the water and pulled back a swirl of icy water. They both rowed as hard as they could. Even so, their little boat was much slower than the motorboat.

Up ahead of them, the boat pulled alongside the same harbor Sherlock and John had rented their boat from. The person with the fishing pole jumped out of the boat and sprinted off to the street. The other person on the boat sent his craft speeding away.

Their feverish rowing paid off and Sherlock and John leapt to shore in pursuit of the bomber. They saw him climb inside a black car which had been waiting for him and glance back at the pier nervously.

"Quickly, John!" yelled Sherlock, sprinting after the car.

They spilled out into the center of the street, running along the center line and ignoring the blaring of the car horns. The black car barreled along ahead of them, slowly but steadily drawing away.

"We'll never catch him," wheezed John.

"Oh, yes, we will!" cried Sherlock. He came to a stop and drew a small mirror out of his pocket. Finding the sun with his mirror, Sherlock angled the sunlight toward the rear-view mirror of the van riding just in front of the black car. From there, the directed sunlight blared right into the eyes of the driver in the black car.

Suddenly, the black car stopped. As Sherlock and John hurried forward, they saw someone climb out of the passenger door.

The figure sprinting in front of them made a beeline across the street.

"He's headed to Waterloo Station!" yelled Sherlock, watching as their prey disappeared into a crowd of commuters.

Sherlock and John plunged into the group themselves, desperately pushing through the closely-packed crowd. With dread, they saw a train roll into the station, the wheezing brakes hissing loudly. The man hurriedly shoved himself into a random car, elbowing people out of the way and glancing back at his hunters, who were still fighting through the crowd.

"He's getting away!" said John, getting buffeted aside by a heavy-set businessman wielding a large suitcase.

"BOMB!" screamed Sherlock.

As soon as he said the word, almost everyone in the station dropped whatever it was they were doing and darted away to the exit, tripping over each other in their haste and fear. A calamitous din resounded throughout the station as people either stormed over to the exit or leapt into the train.

Only Sherlock and John remained after the stampede, and now their path to the train was clear. Just as the doors of the nearest car began to close, they jammed themselves through.

"Sherlock, that was illegal!" said an exasperated John, once the doors had closed behind them.

"That wasn't illegal," said Sherlock as the train started forward. "That was fun."


	4. Chapter 4

After catching his breath sufficiently, Sherlock walked over to the door that led to the next car. The people riding in the car seemed like they wanted to protest at Sherlock and John's actions, but made no move to stop them.

They climbed through three more sets of doors, then emerged into the car that the bomber had vanished into. Just as they moved to go through this door, someone found their voice.

It was a man just below-average height wearing a suit and tie. His hair was a fiery red, which complemented his fuming countenance.

"Hey! What're you doing?" he yelled, moving to the center of the aisle to block their path. "That's illegal."

"Oh, you're very boring, aren't you? Get out of the way," said Sherlock.

When the portly man made no move to get out of the way, Sherlock and John pushed him aside and charged through the next door. There were only six cars on the train, and they had cleared four cars already. That left only one more passenger car and the engine car.

"He's not in here," said Sherlock, looking around at the fifth passenger car.

"On to the last one," John agreed.

They opened the last connecting door and wrenched open the corresponding door in the car ahead of them. The dark underground air whirled past them, threatening to rip Sherlock and John from their small perch.

They carefully crossed and, once they were safely inside, pulled the door shut. Then, they turned around to scout out the new car. This car had a different layout than the previous passenger ones. There was an emergency door directly to their left, as well as a long aisle down the middle. At the end of the passage, in the very front of the train, there was a small compartment and a window.

Sherlock and John started toward the steering compartment, eyes up ahead. Although they got a good view of the steering compartment, they were blind to the long, thin wire stretching across the central aisle.

It ensnared their feet and knocked them down to the ground, knocking the breath out of them. Before they could move, a heavy boot stomped down on both of their backs.

A deep, guffawing laugh came from up above. Sherlock and John tried to turn their heads upward to try to find out where it came from, but the heavy boots kept them pinned to the ground.

"How pathetic," tutted a big, tall man with a thick southern American accent. "Now, I ain't seen nothing like tha' in my life. The best detective in all of Britain, brough' down by a simple tripwire."

He succumbed to another fit of maniacal laughter.

"I'll take tha' gun, if you don't mind," he said, leaning down to grab John's gun from where it lay. He detached the tripwire from both sides of the passageway and bound it around their ankles. "Can't have you puttin' up a struggle. Where're my manners? Come on in and join the party!"

He pulled them roughly into the steering compartment, where two petrified-looking drivers manned the controls. He propped them up on the wall of the train.

From there, they could see their captor. He was a beefy, short-necked man wearing a heavy coat. He sat casually in the corner of the train, holding a gun in his lap.

"What do you want?" asked John, trying in vain to break the tripwire.

"Him," responded the captor darkly. "Sherlock Holmes. I'm going to kill him."

"Well, that's nice," muttered Sherlock.

"I hate you," growled the captor.

"So do loads of other people," said Sherlock. "I mean, you're not the first person to hate me with a passion."

"I despise you for capturing my friend. You're the reason he's in jail."

"Again, that's nothing new."

"...Your snarky comments…"

"Oh!" Sherlock cried excitedly. "Trying to kill me for my snarky comments. Now, that's a first!"

John realized that Sherlock was trying to buy time. If they could delay their demises in time for the train to come to the next stop, they might be able to escape. John reached his hand into his pocket and grabbed his cell phone.

Holding the phone close to his body so that the bomber couldn't see, he opened up a text message to Lestrade.

We have bomber on Tube. Need assistance. Kennington station 5 mins.

JW

"It's no use," said Sherlock. "He won't get there on time. He's still hanging around St. Bartholomew's Hospital removing the bomb."

"But his deputies might."

Sherlock's eyes lit up with hope at the prospect.

"Quiet," snapped the bomber. "Are you that John Watson fellow?"

"Erm, who's John Watson?" lied John to buy time. "I've never heard of that person. My name is Philip Konrad."

"You're lying," said the bomber.

"How very perceptive of you," said Sherlock sarcastically, shaking his head.

John looked back at his phone. Lestrade still hadn't responded.

Sherlock continued to buy more time, but he saw that his captor was itching for the trigger.

"No more delays, Sherlock Holmes," growled the bomber. "The only reason I've been keeping you alive is to see the fear on your face."

He lifted his large gun and, just a few feet away, pointed it at Sherlock's head.

"You should know, Roger Jones, that it is inadvisable to-"

"Hang on, who told you my name?" interjected the bomber.

"I read you like a page in a book," said Sherlock. "The letters are plastered all over your face. Anyway, as I was trying to say earlier, it would be extremely inadvisable for you to shoot that gun in here. The explosive power in that gun would destroy the whole room and take the controls along with it. You may inadvertently strand yourself here with nowhere to run."

Jones bit back a snarl.

"How interesting," observed Sherlock. "You were so caught up with trying to kill me that you ignored the basic logistics necessary to complete your task. You're no gunman, Jones; you're a bomber, through and through."

This last part enraged Jones. "I'll show you my skill at firearms!" he yelled. "But not in here."

Jones dragged them back down the hallway. John wasn't sure if he was imagining it, but the train seemed to be slowing down. Unless he was wrong, the slowing of the train could only mean one thing, that the train was coming into a station.

"The controls won't be damaged if I kill you in here," spat Jones.

He took up a shooting stance in the aperture in front of the emergency door. Slowly, he raised his gun, looking down the sights to be sure that his aim was true. His finger curled around the trigger.

Sherlock gave John a near-imperceptible nod and their bound legs kicked out in unison at their captor. The bomber toppled backwards into the emergency hatch. His hands grabbed around for a handhold to stop himself falling through, and his fingers closed against the very mechanism meant to open the hatch.

He toppled backwards out of the hatch, his gun going off somewhere in midflight.

"After him!" said Sherlock. "We can't afford to let him get away."

In an odd, three-legged gait, they hobbled through the emergency exit. The train hadn't been at a full stop when Jones had fallen out, so they had to walk back a few feet to find where Jones was.

Sherlock leaned down to pick up the fallen gun while John looked at Jones. He was in bad shape; he had been winded by the fall.

"I don't believe it!" cried John, pointing at Jones' arm. "The bullet ricocheted off the ceiling and hit him!"

Sure enough, there was a little indentation on the corresponding section of the wall.

Down below them, there was a sick groan and Jones clenched at his bleeding arm.

Instantly, Sherlock and John doubled over in uncontrollable laughter. Perhaps, some of it was caused by the hysteria inflicted upon them from their near-death experience, but that didn't take away from the sheer hilarity of the situation.

Within a minute, Lestrade's deputies charged through the gate and took Jones into custody.

With surprise, John saw that Lestrade was among the police.

"How did you get here so fast?" asked John.

"I had already left the hospital by the time that you texted," he responded quickly. "Why're you two walking like that?"

"He tied our ankles together," said John.

"It's kevlar, I'm afraid," said Lestrade, trying to stifle a laugh.

"This _isn't_ funny, Lestrade!" insisted Sherlock.

But Lestrade seemed to think it was.

After using a enormous set of loppers to cut the tripwire, Lestrade offered to give them a ride to the hospital, which they gladly accepted. After their ordeal, they didn't want to ride the train again any time soon.

As they rode along in the backseat, John used the time to ask Sherlock about the things that still didn't make sense about the case.

"I have one question. How did you know that his name was Roger Jones? If you didn't have that information to use as a diversion, we probably would've died."

"Simple, really. I had Lestrade here send me the results of the DNA test. I recognized the pattern from a file I had seen earlier regarding the robbery of a bank in Texas, belonging to a man named Roger Jones."

"You remembered an entire human genome?" said Lestrade from the front seat, shocked.

"Yep," said Sherlock, tapping his head. "It's all stored up here."

John shook his head in disbelief. Sometimes he forgot how advanced Sherlock's brain was, then was rudely reminded of it at times like these.

"I hope that Molly is O.K.," said John. "Jones seems like a particularly nasty person. He might've killed her, like you said earlier."

"I'm sure that we're all hoping that's not the case," stressed Lestrade. It was quite obvious from his tone of voice that he was trying to test Sherlock for signs of a conscience.

"Come on, Lestrade," said Sherlock. "You should know by now that I'm not a bloody psychopath."

"He's a high-functioning sociopath," finished Lestrade irritably.

 **Author's note: The next chapter will be the final one. I hope you've enjoyed reading this story! It was fun to write.**


	5. Epilogue

Fifteen minutes later, they pulled up next to St. Bartholomew's Hospital and hopped out of Lestrade's police car. Before Sherlock and John could so much as breathe, Molly had dashed out and encapsulated them both in an enormous hug.

Tear tracks formed rivulets down the front of her face, but she made no move to wipe them away.

"I'm so sorry, you two," she wept. "The Americans forced me to play along with their little game. Jones… he kidnapped me outside the hospital and threatened to kill me and my friends unless I did exactly what he said. I couldn't bear that idea and I had no way to fight him, so I snuck back into the lab and did as he said.

"As soon as I got out of the hospital, I tried to text you, but Brown, the gunman of the duo, shot my phone out of my hand. I returned to my home with every intention of conveying some sort of message, but when I arrived, I saw that it had been completely ransacked. They had been extremely thorough in their search; there was nothing left that I could possibly use to send a message. And as I knew that I was being watched, I didn't dare risk going to see you.

"I was holed up in my apartment for five days. During that time, I made an escape plan. I managed to incapacitate Brown and used a friend's phone to call the police."

"Why do you think Brown and Jones wanted to keep you alive?" asked John.

"I've wondered the same thing, although I'm immensely glad they did," said Molly. "Maybe they were planning on using me to plant more bombs or as a hostage."

Sherlock nodded. "I see nothing wrong with your logic," he said. "Erm… this is slightly uncomfortable. Could you let go of us now?"

Molly blushed profusely when she realized that she was still hugging them.

Sherlock and John sat in their flat a week later. Sherlock was sprawled in his favorite armchair playing his violin and John sat reading the newspaper at the kitchen table. To clear off a space to rest his hands, he had to move two shrunken heads out of the way. Their unseeing eyes stared at John as though they were upset he had moved them.

"Sherlock, where'd you get these shrunken heads, anyway?" asked John, who was thoroughly unnerved by the small, withered heads.

"Amazon," responded Sherlock from the other room.

"I didn't know they did head shrinking in Brazil," said John. "I thought it was done predominantly by the people of Peru and Ecuador."

"No, John. Amazon the _company_."

"They sell shrunken heads?" asked John incredulously.

"If you know where to look."

Just then, a loud thumping sound came from downstairs.

"Package for you, Sherlock," trilled Mrs. Hudson.

Wordlessly, Sherlock and John dropped what they were doing and hurried down the stairs to the front door.

A few delivery men were rolling a large cardboard box through the doorframe. It looked just like the box Mycroft had made his entrance in earlier.

"Mycroft has no style, doing the same thing twice," grumbled Sherlock.

"Sign here, please, Mr. Holmes," said the head delivery man, proffering a clipboard and pen. "We have orders to take the package straight up to the flat."

A few minutes later, the package stood unopened in the middle of the sitting room.

"I wonder why Mycroft felt the need to come all the way up to our flat this time," said John.

"Well, you might as well let him out," chimed Mrs. Hudson. "Mycroft is _such_ a dear. I hope he'll remember what I told him about the refrigerator problem."

Sherlock rolled his eyes as John cut away the cardboard. John peeled back the brown box, revealing a pristine white refrigerator that seemed to glow in its immaculate cleanliness.

Mrs. Hudson squealed in excitement. "Finally! This one's for food and the other's for Sherlock's experiments."

Together, they moved the refrigerator into place next to the other one. John opened the door to the refrigerator and found a note tucked into the deli section. It read:

Dear brother,

We both know that it's not hygenic to mix rotting body parts with food. _Please_ use this one for food you plan on eating and the other for your silly experiments.

Best,

Mycroft

"He's such a considerate person, isn't he?" said Sherlock bitterly. Sherlock secretly liked seeing the revulsion on John's face whenever he opened the refrigerator.

Mycroft sure knew how to ruin the fun things in life.

They ate that evening in the creperie. Winter was starting to relinquish its cold grasp on London, but not by much. Although most of the snow had melted, pockets of melting, brownish snow still sat here and there, where they had been pushed aside by snow plows. Sherlock and John were very thankful for the warm, sugar-dusted crêpes.

"It's been a fulfilling case, don't you think?" asked John. "What should I call it in my blog?"

"How about… The Bombing of Britain?" suggested Sherlock, downing another crêpe.

"I like it," replied John, scribbling the idea on his napkin. "The alliteration is nice."

John was struck by an idea. "That reminds me of something that I picked up at the nearby music supplies store…."

John reached into his pocket and procured a black, rubber piece with four notches.

"It's a practice mute," he said, handing it to Sherlock. "It won't cancel all the noise your violin makes, but at least it will make it sound less like someone is screaming."

Sherlock furrowed his brow in concentration. It was a considerate gift that would allow him to practice his violin without inducing John's wrath. What was that phrase that people used to express gratitude to each other? Oh, yes, that's it...

"Thank you," he eventually said.

"You know, I think that's the first time you've ever said that."

* * *

 **Author's note: Thank** ** _you_** **, readers, for sticking with this story to the end. I must confess that it is a little unfortunate that after 10,000 words, I still have but one review. I don't like to be annoying when it comes for asking for reviews, but seeing how this is the last chapter, I can't think of a better time. Reviews are like crêpes for FanFiction writers (the more you eat, the better you can write).**

 **Thank you, wonderful readers, and please review!**


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